Ext.override(Ext.grid.GridPanel, {
	getExcelXml: function(includeHidden) {
		var worksheet = this.createWorksheet(includeHidden);
		var totalWidth = this.getColumnModel().getTotalWidth(includeHidden);
		return '<?xml version="1.0" encoding="utf-8"?>' +
		'<ss:Workbook xmlns:ss="urn:schemas-microsoft-com:office:spreadsheet" xmlns:x="urn:schemas-microsoft-com:office:excel" xmlns:o="urn:schemas-microsoft-com:office:office">' +
		'<o:DocumentProperties><o:Title>' + (this.title===undefined?'':this.title) + '</o:Title></o:DocumentProperties>' +
		'<ss:ExcelWorkbook>' +
		'<ss:WindowHeight>' + worksheet.height + '</ss:WindowHeight>' +
		'<ss:WindowWidth>' + worksheet.width + '</ss:WindowWidth>' +
		'<ss:ProtectStructure>False</ss:ProtectStructure>' +
		'<ss:ProtectWindows>False</ss:ProtectWindows>' +
		'</ss:ExcelWorkbook>' +
		'<ss:Styles>' +
		'<ss:Style ss:ID="Default">' +
		'<ss:Alignment ss:Vertical="Top" ss:WrapText="1" />' +
		'<ss:Font ss:FontName="arial" ss:Size="10" />' +
		'<ss:Borders>' +
		'<ss:Border ss:Color="#e4e4e4" ss:Weight="1" ss:LineStyle="Continuous" ss:Position="Top" />' +
		'<ss:Border ss:Color="#e4e4e4" ss:Weight="1" ss:LineStyle="Continuous" ss:Position="Bottom" />' +
		'<ss:Border ss:Color="#e4e4e4" ss:Weight="1" ss:LineStyle="Continuous" ss:Position="Left" />' +
		'<ss:Border ss:Color="#e4e4e4" ss:Weight="1" ss:LineStyle="Continuous" ss:Position="Right" />' +
		'</ss:Borders>' +
		'<ss:Interior />' +
		'<ss:NumberFormat />' +
		'<ss:Protection />' +
		'</ss:Style>' +
		'<ss:Style ss:ID="title">' +
		'<ss:Borders />' +
		'<ss:Font />' +
		'<ss:Alignment ss:WrapText="1" ss:Vertical="Center" ss:Horizontal="Center" />' +
		'<ss:NumberFormat ss:Format="@" />' +
		'</ss:Style>' +
		'<ss:Style ss:ID="headercell">' +
		'<ss:Font ss:Bold="1" ss:Size="10" />' +
		'<ss:Alignment ss:WrapText="1" ss:Horizontal="Center" />' +
		'<ss:Interior ss:Pattern="Solid" ss:Color="#8DB4E3" />' +
		'</ss:Style>' +
		'<ss:Style ss:ID="even">' +
		'<ss:Interior ss:Pattern="Solid" ss:Color="#DBE5F1" />' +
		'</ss:Style>' +
		'<ss:Style ss:Parent="even" ss:ID="evendate">' +
		'<ss:NumberFormat ss:Format="[ENG][$-409]dd\-mmm\-yyyy;@" />' +
		'</ss:Style>' +
		'<ss:Style ss:Parent="even" ss:ID="evenint">' +
		'<ss:NumberFormat ss:Format="0" />' +
		'</ss:Style>' +
		'<ss:Style ss:Parent="even" ss:ID="evenfloat">' +
		'<ss:NumberFormat ss:Format="0.00" />' +
		'</ss:Style>' +
		'<ss:Style ss:ID="odd">' +
		'<ss:Interior ss:Pattern="Solid" />' +
		'</ss:Style>' +
		'<ss:Style ss:Parent="odd" ss:ID="odddate">' +
		'<ss:NumberFormat ss:Format="[ENG][$-409]dd\-mmm\-yyyy;@" />' +
		'</ss:Style>' +
		'<ss:Style ss:Parent="odd" ss:ID="oddint">' +
		'<ss:NumberFormat ss:Format="0" />' +
		'</ss:Style>' +
		'<ss:Style ss:Parent="odd" ss:ID="oddfloat">' +
		'<ss:NumberFormat ss:Format="0.00" />' +
		'</ss:Style>' +
		'</ss:Styles>' +
		worksheet.xml +
		'</ss:Workbook>';
	},

	createWorksheet: function(includeHidden) {

		//Calculate cell data types and extra class names which affect formatting
		var cellType = [];
		var cellTypeClass = [];
		var cm = this.getColumnModel();
		var totalWidthInPixels = 0;
		var colXml = '';
		var headerXml = '';
		for (var i = 0; i < cm.getColumnCount(); i++) {
			if (includeHidden || !cm.isHidden(i)) {
				var w = cm.getColumnWidth(i)
				totalWidthInPixels += w;
				colXml += '<ss:Column ss:AutoFitWidth="1" ss:Width="' + w + '" />';
				headerXml += '<ss:Cell ss:StyleID="headercell">' +
										 '<ss:Data ss:Type="String">' + cm.getColumnHeader(i) + '</ss:Data>' +
										 '<ss:NamedCell ss:Name="Print_Titles" /></ss:Cell>';
				var fld = this.store.recordType.prototype.fields.get(cm.getDataIndex(i));
				if (fld !== undefined) {
					switch(fld.type) {
						case "int":
							cellType.push("Number");
							cellTypeClass.push("int");
							break;
						case "float":
							cellType.push("Number");
							cellTypeClass.push("float");
							break;
						case "bool":
						case "boolean":
							cellType.push("String");
							cellTypeClass.push("");
							break;
						case "date":
							cellType.push("DateTime");
							cellTypeClass.push("date");
							break;
						default:
							cellType.push("String");
							cellTypeClass.push("");
							break;
					}
				}else{
					cellType.push("String");
					cellTypeClass.push("");
				}
			}
		}
		var visibleColumnCount = cellType.length;

		var result = {
			height: 9000,
			width: Math.floor(totalWidthInPixels * 30) + 50
		};

		//Generate worksheet header details.
		var t = '<ss:Worksheet ss:Name="' + (this.title===undefined?'sheet1':this.title) + '">' +
						'<ss:Names>' +
						'<ss:NamedRange ss:Name="Print_Titles" ss:RefersTo="=\'' + this.title + '\'!R1:R2" />' +
						'</ss:Names>' +
						'<ss:Table x:FullRows="1" x:FullColumns="1"' +
						' ss:ExpandedColumnCount="' + visibleColumnCount +
						'" ss:ExpandedRowCount="' + (this.store.getCount() + 2) + '">' +
						colXml +
						'<ss:Row ss:Height="38">' +
						'<ss:Cell ss:StyleID="title" ss:MergeAcross="' + (visibleColumnCount - 1) + '">' +
						'<ss:Data xmlns:html="http://www.w3.org/TR/REC-html40" ss:Type="String">' +
						'<html:B><html:U><html:Font html:Size="15">' + (this.title===undefined?'':this.title) +
						'</html:Font></html:U></html:B></ss:Data><ss:NamedCell ss:Name="Print_Titles" />' +
						'</ss:Cell>' +
						'</ss:Row>' +
						'<ss:Row ss:AutoFitHeight="1">' +
						headerXml +
						'</ss:Row>';

		//Generate the data rows from the data in the Store
		for (var i = 0, it = this.store.data.items, l = it.length; i < l; i++) {
			t += '<ss:Row>';
			var cellClass = (i & 1) ? 'odd' : 'even';
			r = it[i].data;
			var k = 0;
			for (var j = 0; j < cm.getColumnCount(); j++) {
				if (includeHidden || !cm.isHidden(j)) {
					var v = r[cm.getDataIndex(j)];
					t += '<ss:Cell ss:StyleID="' + cellClass + cellTypeClass[k] + '"><ss:Data ss:Type="' + cellType[k] + '">';
					if (cellType[k] == 'DateTime') {
						t += v.format('Y-m-d');
					} else {
						t += (v===undefined?'':v);
					}
					t +='</ss:Data></ss:Cell>';
					k++;
				}
			}
			t += '</ss:Row>';
		}

		result.xml = t + '</ss:Table>' +
								'<x:WorksheetOptions>' +
								'<x:PageSetup>' +
								'<x:Layout x:CenterHorizontal="1" x:Orientation="Landscape" />' +
								'<x:Footer x:Data="Page &amp;P of &amp;N" x:Margin="0.5" />' +
								'<x:PageMargins x:Top="0.5" x:Right="0.5" x:Left="0.5" x:Bottom="0.8" />' +
								'</x:PageSetup>' +
								'<x:FitToPage />' +
								'<x:Print>' +
								'<x:PrintErrors>Blank</x:PrintErrors>' +
								'<x:FitWidth>1</x:FitWidth>' +
								'<x:FitHeight>32767</x:FitHeight>' +
								'<x:ValidPrinterInfo />' +
								'<x:VerticalResolution>600</x:VerticalResolution>' +
								'</x:Print>' +
								'<x:Selected />' +
								'<x:DoNotDisplayGridlines />' +
								'<x:ProtectObjects>False</x:ProtectObjects>' +
								'<x:ProtectScenarios>False</x:ProtectScenarios>' +
								'</x:WorksheetOptions>' +
								'</ss:Worksheet>';
		return result;
	}
});